This invention relates to an improved method for introducing getter material into an evacuated cavity, and more particularly to a method especially useful with ring laser gyros.
Alkaline earth materials, commonly barium, are widely used as getters to scavenge residual gases in high vacuum devices. Because of the extreme reactiveness of these materials with air, commercially available getter material are usually alloyed with aluminum or other materials in order to reduce their reactiveness.
In ring laser gyros of which applicant is aware, a getter assembly consisting of a snap ring welded to a getter pan containing the getter material is clamped inside the gyro. The getter material is flashed and the gyro closed off at its pinch tube, leaving the getter assembly inside the gyro. This system has several disadvantages. Particles shed from the delivery system due to shock, vibration, and/or temperature variations, can contaminate the gyro and reduce its useful life. Further, a certain amount of contaminated gas is emitted from the getter material just before it flashes. Also, some contaminating particles may be rubbed off during insertion of the getter delivery system into the gyro.
An object of this invention is an improved method for depositing getter material into an evacuated cavity of a ring laser gyro or other similar executed cavity.
Briefly, this invention contemplates the provision of an improved method in which getter material is flashed outside of the evacuated space. Getter atoms are formed into a beam directed toward a predetermined region within the device itself.